1. Field of the Invention
The present invention relates to a braking system of a rail car having a truck traveling on a rail. More particularly, the present invention relates to an apparatus for detection and abatement of excessive oscillatory movement of the truck with respect to the rail.
2. Description of the Prior Art
Truck hunting is a condition in which the wheel set or truck of a rail car begins to oscillate from side to side between the rails of the track while being moved along the track by a train locomotive. The oscillation may be caused by uneven Wear of truck components, defects in the track or a variety of other problems. The oscillation results in rapid wear of the truck components and the track. In addition, truck hunting may result in damage to cargo carried by the rail car, as well as instability during operation which may lead to derailment.
In response to this problem, locomotive engineers apply the brakes of the train upon feeling the side-to-side, oscillatory movement. By applying the brakes, the period of the oscillation is changed, causing the truck hunting to subside.
Detection of truck hunting, however, is relatively difficult, especially on freight trains where the locomotive engineers may be a great distance from a rail car experiencing truck hunting. As a result, a truck hunting condition may go undetected for long periods of time, leading to the above-mentioned damage and instability.
In addition, the engineer must manually apply the brakes upon feeling the truck hunting condition. Such application of the brakes by an engineer often results in over-braking which leads to reduced efficiency and increased wear on brake components.